©
National Instruments Corp.
9
FP-AI-100 and cFP-AI-100
Isolation and Safety Guidelines
Caution
Read the following information before
attempting to connect the [c]FP-AI-100 to any circuits
that may contain hazardous voltages.
This section describes the isolation of the [c]FP-AI-100 and its
compliance with international safety standards. The field wiring
connections are isolated from the backplane and the inter-module
communication bus. The isolation barriers in the module provide
250 V
rms
Installation Category II continuous isolation, verified by
2,300 V
rms
, 1 minute dielectric withstand test. The [c]FP-AI-100
provides
double insulation
(compliant with IEC 61010-1) for
working voltages of 250 V
rms
1
. Safety standards (such as those
published by UL and IEC) require the use of double insulation
between hazardous voltages and any human-accessible parts or
circuits.
Never
try to use any isolation product between human-accessible
parts (such as DIN rails or monitoring stations) and circuits that
can be at hazardous potentials under normal conditions, unless the
product is specifically designed for such an application, as is the
[c]FP-AI-100.
Even though the [c]FP-AI-100 is designed to handle applications
with hazardous potentials, follow these guidelines to ensure a safe
total system:
•
There is no isolation between channels on the [c]FP-AI-100.
If a hazardous voltage is present on any channel, all channels
are considered hazardous. Make sure that all other devices and
circuits connected to the module are properly insulated from
human contact.
•
Do
not
share the external supply voltages (the V and C
terminals) with other devices (including other FieldPoint
devices), unless those devices are isolated from human contact.
•
For Compact FieldPoint, you
must
connect the protective earth
(PE) ground terminal on the cFP-BP-
x
backplane to the system
safety ground. The backplane PE ground terminal has the
following symbol stamped beside it:
. Connect the
1
Working voltage
is defined as the signal voltage plus the common-mode voltage.
Common-mode voltage
is the voltage of the module with respect to ground.
